As conventional joining method and joining body, Patent Document 1 disclose the following. A joining component is formed by a first divisional body and a second divisional body being joined with each other, the first divisional body is provided with an attachment portion, and the second divisional body is provided with a fitting portion which can be fitted to the attachment portion. A welding portion which is melted by application of a high-frequency wave or an ultrasonic wave is provided between the attachment portion and the fitting portion. With the attachment portion and the fitting portion fitted to each other, the attachment portion and the fitting portion are welded via the welding portion, whereby the first divisional body and the second divisional body are joined with each other.
As other conventional joining method and joining body, Patent Document 2 discloses an ultrasonic joining method in which ultrasonic vibration is applied to joining portions provided on the surfaces of first and second works that face each other while the joining portions are in contact with each other, thereby welding these works. At least one of the joining portions of the first and second works has a receiving groove, and the first work joining portion is formed between first and second ribs. By an ultrasonic joining device, ultrasonic vibration is applied with the first rib and the joining portion of the second work in contact with each other, whereby a melted member melted from the first rib fills the space between the first rib and the second rib. After the end of the second rib comes into contact with the joining portion of the second work, at any point of time before the facing surfaces of the first and second works except the receiving groove come into contact with each other, the application of ultrasonic vibration is finished. The receiving groove stores at least the melted member melted from the first rib.
As still other conventional joining method and joining body, Patent Document 3 discloses the following. In order to fix a joining element to a substantially cylindrical or slightly conical wall, of an opening of an object, which extends away from the opening, the joining element has a substantially cylindrical or slightly conical wall fixation portion having a shape and a size adapted to the wall. The peripheral surface of the wall fixation portion includes a thermoplastic material, and is provided with an energy director, i.e., a rib and/or a protrusion tapered outward to become a somewhat sharp edge or tip. For the purpose of fixation, in this wall fixation region which has a cross section slightly larger than that of the wall of the opening, mechanical vibration is applied to the near-side end of the joining element, and at the same time, the thermoplastic material of the peripheral surface of the wall fixation portion of the joining element is at least partially liquefied to be thrusted into a hole or recess/protrusion part of the wall or into a cavity specially provided therein, and the joining element is fixed there when the thermoplastic material is solidified again.